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dmitriy
Asked:2022-01-11 21:24:57 +0000 UTC2022-01-11 21:24:57 +0000 UTC

按语言名称排序无法正常工作，但默认语言除外

  • 772

有一个名称为语言列表的对象数组和一个从这个列表中选择语言的数组 selectedLanguagesId

const list = [
  {
    id: 2,
    name: 'Dutch'
  },
  {
    id: 3:
    name: 'English'
  },
  {
    id: 1:
    name: 'Italian'
  },
  ...
];

let selectedLanguagesId = [3, 2, ...];
const defaultLanguageId = 3;

需要默认语言总是在前面，其余按名称排序。我的脚本的问题是它不能正常工作——它没有把默认语言放在前面。我将不胜感激

getSelectedLanguages() {
  return this.selectedLanguagesId
    .map((id) => this.list.find((lang) => lang.id == id))
    .sort((a, b) => {
      if (a.id == this.defaultLanguageId || b.id == this.defaultLanguageId) return 0;
      if (a.name > b.name) return 1;
      if (a.name < b.name) return -1;

      return 0;
    });
},
javascript

2 个回答

  1. Best Answer

    if (a.id == this.defaultLanguageId || b.id == this.defaultLanguageId) return 0;

    return 0意思是“不要改变这对元素的位置”。你只需要向上推所需的对象：

    let test = {
  list: [
    { id: 2, name: "Dutch" },
    { id: 3, name: "English" },
    { id: 1, name: "Italian" },
  ],
  selectedLanguagesId: [3, 2, 1],
  defaultLanguageId: 3,

  getSelectedLanguages() {
    return this.selectedLanguagesId
      .map((id) => this.list.find((lang) => lang.id == id))
      .sort((a, b) => {
        if (a.id == this.defaultLanguageId) return -1; // <--
        if (b.id == this.defaultLanguageId) return 1;  // <--
        
        if (a.name > b.name) return 1;
        if (a.name < b.name) return -1;

        return 0;
      });
  },
};

console.log( test.getSelectedLanguages() );

    • 2

  2. 也许你想要这样的东西？按默认数组过滤和排序。

    在示例中，添加了俄语，但它不包含在所选语言列表中。

    const list = [
  {
    id: 2,
    name: 'Dutch'
  },
  {
    id: 5,
    name: 'Russian'
  },
  {
    id: 3,
    name: 'English'
  },
  {
    id: 1,
    name: 'Atalian'
  }
];

function getSelectedLanguages(list) {
  let selectedLanguagesId = [1, 2, 3];
  const defaultLanguageId = 3;
  
  return list
    .filter( item => selectedLanguagesId.includes(item.id))
    .sort((a, b) => 
      a.id == defaultLanguageId ? -1: b.id == defaultLanguageId? 1 : a.name > b.name? -1: a.name < b.name? -1: 0);
}

let result  = getSelectedLanguages(list);

console.log(result);

    • 1

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